Method of producing ingots free from blow-holes.



W. P. M. MGGARTY. METHOD OF PRODUCING INGOTS FREE PROM BLOW HOLES. APPLICATION FILED JULY12, 1907.

898,770. Patented Sept,.15, 1908.

2 SHEETSSHEET 1.

EXHAUST W. P. M. MCCARTY. METHOD OF monnome INGOTS FREE FROM BLOW HOLES.

APPLIOATION FILED JULY lZ, I907.

Patented Sept. 15, 1908.

2 SHEETSSHEET 2.

LNVENTOR UNITED STATES PATENT onnron.

wI 1AM F. MASON MoGARTY, 0F PLEASANTVILLE, NEW YORK, ASSIGNOR OF ONE-FOURTH O GEORGE O. EATON, ONE'FOURTH TO THOMAS M. AGKEN, AND ONE-THIRTIETH TO ALEXANDER J.-GUTTMAN, OF YORK, N. Y.

METHOD OF PRODUCING INGOTS FREE FROM BLOW-HOLES.

Specification of Letters Patent.

Patented Sept. 15, 1908;

Applicationflled July 12, 1907. Serial No, 383,488.

produce therefrom ingots which are homogeneous, of a distinctly fibrous or 'lamellar structure; neither granular nor crystalline, and wholly free. from blowholes, fissures,

' flaws and seams.

' resulting from t nitro on of the air with the carbon in the ineta These gases are present in varying quantities in the metal when it is ready to be poured, and their presence in the metal results in the roductlon of blowholes', granulation and 0t er imperfections in the resulting product. The presence of the gases also chemically affects the resulting metal, particularly 1n the case of cyanogen, which renders it friable and short.

Under the practice which has heretofore obtained in the art, it has only been possible to eliminate the occluded gases, with the consequent lack of homogeneity and the presence ofblowholes, flaws, and the like, by long continued manipulation of the cast metal, either by rolling or forging it under heavy steam I hammers while hot. It is known in the art that the occluded gases cannot be wholly eliminated by such manipulation, and that the finished product is necessarily of an uncertain quality'by reason of unevenness of texture and the presence of weak spots which ins ction cannot disclose.

a result of long continued experiment,

I have developed a process by which occluded gases in molten metal may be wholly removed, in a simple and'economical manner, without the necessity of prolonged forging or rolling,

and with the result that the molten metal so treated may be cast into in ots or blooms, followed with but a single 'ro ling or forging. I have found that plates, rails, beams, and other finished products produced from metal, which has been treated according to my process, are not only homogeneous 1n structure,

' but have a-distinct fibrous or lamellar structure, neither granular nor crystalline.

In the accompanying drawing Figure 1 is a sectional view of a converter 1n which my process may be advantageously carried out.

ig. 2 is a vertical section ofa form of mold which is well adapted for use in connection with my process, and Fig. 3 is a view in side elevation of a supporting frame for the said mold.

In the practice of my process I take steel which has been subjected to treatment with atmospheric air in a Bessemer converter until the carbon has been sufiiciently eliminated. Instead ,of then pouring the metal into the ingot molds as is the present practice, I introduce superheated steam into the metal through thetwyers for a eriod of from ten to thirty minutes. I emp 0y the su erheated steam under high 'tension, an in small quantities, introducing it in intermittent jets or impulses. The steam, upon coming in contact with the molten metal, be-

comes decomposed into its elements, and as the steam is injected in intermittent impulses, the decomposition results in a series of explosionsin the mass of the metal, the

oxygen and hydrogen combining with the oceluded gases, eliminating them from the metal. When the blow of superheated .steam has been ofsuflicient duration, which will be determined by practice on the metal under treatment, I close the twyers and the upper opening of the converter, and subject the molten metal to the action of a vacuum by withdrawing air from the converter, at or near the upper portion thereof, by means of a powerful exhaust ump. The a tion of the vacuum results in t e removal of t e-remaining occluded gases which I have found to be renderedeasily removable by the treatment with superheated steam.

I have found that it is possible to remove a considerable portion of the occluded gases from molten metal by the action of superheated steam alone, and by the action of a vacuum alone, but my experiments have demonstrated that by first treating the metal with superheated steam, as hereinbefore described, and then, preferably at once, subjecting the metal to the action of a vacuum, I am able to obtain results in the elimination of occluded gases which are greatly in excess of the sum or aggregation of the results of each of the operations conducted separately. It thus a pears that the action of the superheated steam not only serves to eliminate a considerable portion of the occluded gases, but by chemical combination or otherwise, to render'said gases capable of ready and complete removal by the action of a vacuum. After the metal has been subjected to the action-of a vacuum for a period of from ten to thirty minutes according to the character of the metal under treatment, to be determined by practice, I withdraw the metal from the converter and pour the same into ingot molds which are subject to the action of a vacuum. The metal is introduced into the molds through the bottom thereof by'means of an inverted siphon or goose-neck, the top'of the mold being in communication with a suitable exhaust pump. l

The converter shown by way of exam le in Fig. 1 of the drawing is well adapted lbr use in carrying out my process. ure, A represents the converter which may be of the usual Bessemer converter construction. Twyer B is provided at the lower end of the body of the converter and by means of this, the molten metal may be supplied at will with air from pipe 0 or superheated steam frompipe D. Valves E and F are supplied to control the passage of air and steam.

A cover H is provided which forms a substantially air tight joint with the top of the converter A. A vacuum is produced in the body of the converter by means of an exhaust pump (not shown) connected with exhaust pipe The mold proper comprises two semicylindrical sections 1 and 2 of suitable materlal, adapted to fit together, and be hermetically sealed at their oints of contact.

mold is provided w1th the metal-receiving opening or reservoir 3 in which the ingot is formed. An inverted siphon or goose-neck 4, preferably of terra cotta or like suitable material, is connected with an opening 5 in I the base of, the mold. A flange 6 carried by the siphon 4 fits closely against the base of the mold and serves to prevent leakage.

pipe7 connected with a suitable exhaust ump, not shown, leads to the upper openmg 8 of the mold and serves to wit draw air therefrom. a

In the fig- The I A flange 9 carried by the pipe 7 fits tightly against the top of the mold and serves to prevent the entrance of air through the opening 8.

After the mold has been set up, a supporting frame or casing 10 is secured around it. This frame or casing comprises a base 11 having two hollow semi-cylindrical sides pivoted thereto by hinges 12 and 13. Hinged top or cover portions 14 and 15 are secured to the sides by hinges 16 and 17. Adjustable bands 18 and 19 surround the frame or casing 10'when in position about the mold, and these bandsare adapted to force the two arts of the mold tightly together by means of adjusting screws 20 and 21.

' In using the mold, the molten metal-is introduced through the si hon a under the action of a vacuum until t e metal reaches the level X-X. The vacuum is maintained until, the metal is set or hardened. I have found in the ractice of my process that I am able to elimmate all ofithe occluded gases from the metal and to maintain the metal free from the presence of such occluded gases until the final ingot is produced. I have also found; that ingots produced in accordance with my process are entirely homoge- I 'neous and possessed of a distinctly fibrousor -lamellar structure, and to be free fromfissures, flaws, blowholes or other weak spots.

Having thus described my invention, I claim:

1. A rocess of treating metal to remove occlude or otherwise held gases therefrom which consists in subjecting said metal, while in the same molten state, to the action of superheated steamand to the action of a vacuum. 7

2. A rocess of treating metal 'to remove occlude or otherwise held gases therefrom which consists in subjecting sai d metal, while in the same molten state, to the action of superheated steam in intermittent jets or impulses and to the action of a vacuum.

' 3. A rocess of treating metal to remove occluded or otherwise held gases therefrom which consists infirstpassing superheated steam through said metal, while in a molten state, and then subjecting said metal, while in the same molten state, to the action of a vacuum. I

4. A rocess of treating metal to remove occlude or otherwise held gases therefrom which consists in passing su erheated steam in intermittent jets 'or impu ses through the metal, while'in a molten state, and then subjecting said metal, while in the same molten state, to'the-action of'a vacuum.

' 5. The hereindescribed method of producing ingots free from blowholes which consists in eliminating occluded or otherwise held gases from molten metal by treating the metal, while in the same molten state, with superheated steam and vacuum, withdrawaction of a vacuum, and permitting said mold under the action of a vacuum, and permetal to set or harden under diminished atmitting said metal to set or harden under mospherie pressure. diminished atmos heric ressure.

6. The hereindescribed method of produc- In testimony w ereof aflix my signature 5 ing inggls free from Ilolowholes which conin presence of two witnesses.

' .sists in owin su .er eated steam in inter- T mittent jets 1- ir iipulses through molten WILLIAM MAM) Q metal, then subjecting said metal, while in Witnesses: the same molten state, to the action of a AIDA F. MCOARTY,

10 vacuum, then withdrawing said metal into a ANNA R. WILCOX. 

